<p>Opto-electronic and thermoelectric properties of derivatives of the Zintl phase ternary SrInAs system are carried out in P63/mmc, Pnma, Pnnm and Pbam space groups via DFT through WEIN2K to find out the effect of elemental concentration on their physical properties. SrIn₂As₂, Sr₃InAs₃, Sr₃In₂As₄ compounds are direct bandgap semiconductors at r symmetry point, and Sr₅In₂As₆ is direct bandgap semiconductor at M symmetry point. The direct bandgap nature is indicated by their electronic properties, range between 0.08 and 0.76&#xa0;eV. The bandgap of these compounds changes with variation in elemental concentration. All materials are active in the infrared spectrum because of their optical properties. Their optical dynamic properties make them potential candidates for application in optoelectronic devices. Their Seebeck coefficient and power factor make them excellent thermoelectric materials for thermoelectric power generation as nano-thermocouples and the greater elemental concentration in Sr₅In₂As₆ make them efficient thermoelectric materials among the series.</p> Graphic abstract <p></p>